Resetting means for sectionalizing switch

ABSTRACT

A quick reset means is disclosed for a sectionalizing switch having a trip device which is advanced to a tripping position to cause the switch operating means to move to an open position and open the switch contacts. The reset means includes resilient means held loaded by the switch operating means when the latter is in its closed position. The reset means is movable into impacting engagement with the trip mechanism due to the force supplied by the resilient means. Thus, when the operating means is tripped and moved to its open position, the reset means is released and impacts the trip mechanism to quickly reset the trip mechanism.

United States Patent I2 NH UN I RESET'I'ING MEANS FOR SECTIONALIZING SWITCH l4 Claims, 3 Drawing Fig.

lnt.Cl. .v. ...H0ll|75/04 FieldoiSeor-ch i 4 A 335/3216,

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[56] Relerences Cited UNITED STATES PATENTS 2.828.383 3ll9$8 Uhrig335/29 3,344,372 9/l967 Heilmln l. 335/28 Primary Examiner-HaroldBroorne Attorney-Richard C. Ruppin ABSTRACT: A quick reset means isdisclosed for s sectionalizing switch having a trip device which isadvanced to a tripping position to cause the switch operating means tomove to an open position snd open the switch contacts. The reset meansincludes resilient means held loaded by the switch operating means whenthe latter is in its closed position. The reset means is movable intoimpacting engagement with the trip mechanism due to the force suppliedby the resilient means. Thus, when the operating means is tripped andmoved to its open position, the reset means is released and impacts thetrip mechanism to quickly reset the trip mechanism.

RESE'ITING MEANS FOR SECTIONALIZING SWITCH This invention relates tocircuit interrupters and, in particular, to a reset mechanism for asectionalizing switch.

Automatic circuit interrupters are commonly used as sectionalizingswitches in electrical distribution systems where it is desirable tointerrupt and isolate a single section of the system having a permanentfault condition. Typically, the sectionalizing switch is connected inthe branch of a system in series with a backup device such as anautomatically reclosing circuit breaker. The sectionalizing switch iscoordinated with the reclosing circuit breaker so that the latter willopen the system several times before the sectionalizing switch locksopen during an interval when the backup device is opened. To effect suchcoordination. the sectionalizing switch will usually have a trippingmechanism which is stepped to a tripping posi' tion during the openingand reclosing operation of the recloser. After a predetermined number ofreclosing and opening operations, the trip mechanism of thesectionalizing switch will cause the switch to open during an opencircuit interval.

A problem that arises when the sectionalizing switch is manuallyreclosed immediately after tripping and locking open is that thetripping mechanism has not had time to reset to its normal position sothat the operation of the sectionalizing switch will again becoordinated with the reclosing circuit breaker. The result is that thesectionalizing switch may immediately open because the trippingmechanism is still in its trip positic... Thus, the sectionalizingswitch will attempt to interrupt fault current far in excess of iisinterrupting rating before the reclosing circuit breaker has anopportunity to open circuit the system.

An object of this invention is to provide a circuit interrupter having atrip mechanism and a trip mechanism reset means which will quickly resetthe trip mechanism immediately after each opening and lockout operationof the circuit interrupter.

Another object of this invention is to provide a resetting means for thetrip mechanism of a circuit interrupter which will accurately reset thetripping mechanism to a predetermined position.

The objects of the invention are achieved by providing a reset mechanismfor the tripping means of a circuit interrupter or sectionalizing switchwhich is actuated by the contact operating means of the circuitinterrupter. The reset mechanism is moved to a high impact position bythe contact operating means when the latter is moved to its closedposition. The reset mechanism is held in the high impact position by thecontact operating means until the operating means is tripped by thetripping means whereupon the reset mechanism is released to impact thetripping means and quickly return the tripping means to its normalposition in preparation for another tripping operation.

Other objects and advantages of the invention will in part be obviousand will in part appear hereinafter. For a fuller understanding of thenature and objects of the invention, reference should be had to thefollowing detailed description taken in connection with the accompanyingdrawings in which:

FIG. I is an elevational view, partially in section. showing a circuitinterrupter having its contact operating means in a closed position andthe reset means of the invention in a fully biased position;

FIG. 2 is an elevational view similar to FIG. 1, partially in sectionand with parts removed, showing the tripping mechanism at its normal orreset position and the reset mechanism in a biased position; and

FIG. 3 is an' elevational view showing the tripping mechanism and thereset mechanism of the invention subsequent to a tripping and resetoperation.

Referring to the drawings, the circuit interrupter is shown to bemounted within a tank 2 partially filled with insulating oil 4. The tank2 is closed by a cover 6 secured to the tank 2 by suitable means such asbolts 10. Insulating bushings 12, only one of which is shown, extenddownwardly into the tank 2 and carry cable terminals I4 at their upperends and terminals 16 at their lower ends.

With reference to FIG. 1, a contact assembly 24 is provided whichincludes the insulating support member 28, the stationary contacts 30mounted on support member 28, the movable contacts 32 and the slide rod34. The insulating members 22 are attached to the cover 6 and extenddownwardly into the tank 2 to support the contact assembly 24. The sliderod 34 is slidably supported on the support member 28 and slides to adownward position in which the stationary contacts 30 and movablecontacts 32 are engaged, shown in FIG. I, and to an upward position inwhich said contacts 30 and 32 are disengaged.

A portion of a contact operating means 36 is shown in its closedposition in FIGS. 1 and 2 and in its open position in FIG. 3. The closedposition of the contact operating means 36 corresponds to the engagedposition of the stationary contacts 30 and movable contacts 32 and theopen position of the contact operating means 36 corresponds to thedisengaged position of the contacts 30 and 32. As shown in FIG. 2, thecontact operating means 36 includes a toggle link mechanism 3! pivotallyattached to the slide rod 34 by pin 50, a latch mechanism 40 supportedon the toggle mechanism 38 and opening spring means 42. The spring means42 is connected between the pin 50 and the inside of cover 6 by meansnot shown. The toggle link mechanism 38 includes an upper link arm 44and a lower double-arm link 46 pivotally connected by the pin 48. Thelatch mechanism 40 is supported between the arms of the double-arm link46 and latches the toggle mechanism 38 so that it will not collapse toallow movement upward of the slide rod 34 and the disengagement ofcontacts 30 and 32 by the opening spring means 42. Other components ofthe contact operating means 36 are not shown inasmuch as they form nopart of the present invention. It is sufficient to say for the presentpurposes that the parts of the contact operating means 36 which are notshown operate generally to cause the engagement and disengagement of thecontacts 30 and 32. Contact operating means of a type suitable for usein the present invention are shown and described in detail in copendingapplication Ser. No. 745,572, filed July 17, 1968, and assigned to theassignee of the present invention.

FIGS. 1 and 2 show a trip mechanism 70 mounted on the support member 28and an overcurrent sensing means designated generally by the numeral 50.The trip mechanism 70 includes the trip piston 72. The overcurrentsensing means 50 is of a type well known in the art and includes asolenoid coil 5l electrically coupled to the line in which the circuitinterrupter is connected through the conducting strap 58 connectedbetween solenoid terminal 56 and terminal I6 and the conducting cable 60connected between solenoid terminal 62 and stationary contact 30. Asolenoid plunger 52 is biased by a spring means 55 in an upwarddirection within the sleeve 54 (see FIGS. 2 and 3). The plunger 52 ispulled downward and held against the biasing force of the spring means55 by the solenoid coil 52 when it is energized and a predeterminedcurrent value flows through it. Upon deenergization of the solenoid coil51, the plunger 52 is released and the spring means 55 urges itupwardly. The overcurrent sensing means 50 includes valve means (notshown) for pumping oil 4 from the tank 2 through an opening (not shown)in plunger 52 to the top 53 of the plunger 52. A predetermined volume ofoil 4 is displaced to the top 53 of the plunger 52 each time the plunger52 is pulled downward by the solenoid coil 51. Upon deenergization ofthe solenoid coil 51, the spring means 55 moves the plunger 52 upward toforce oil 4 through the impulse valve 64 and into the sleeve 54 belowtrip piston 72. The trip piston 72 is thereby moved upward within thesleeve 54 a distance determined by the volume of oil forced through theimpulse. valve 64. The impulse valve 64 is of a well known type whichpermits flow of liquid through it while minimizing pressure resultingfrom the flow of the liquid. When the circuit breaker is utilized as asectionalizing switch connected on the load side of a reclosing circuitbreaker. the solenoid coil 5] will be deenergized and energized eachtime the recloser performs an opening and closing operation. Thus, thetrip piston 72 will be moved upward in a series of steps eachcorresponding to an opening and closing operation of the reclosingcircuit breaker. As described in detail hereinafter, when the trippiston 72 is stepped to a trip position, the trip mechanism 70 willcause the sectionalizing switch to open.

For a more complete description of an overcurrent sensing means usablein the illustrated circuit interrupter, reference is made to US. Pat.No. 2,52l,l94, issued Sept. 5, 1960, and assigned to the assignee of theinstant invention.

The trip mechanism 70 includes the trip piston 72 and the trip lever 74pivotally mounted on the support member 28. The trip lever 74 has an arm76 including a bifurcated end 78 extending to a position above thesleeve 54. A finger 80 is adjustably mounted between the bifurcations ofthe end 78 and extends into the sleeve 54. As shown in FIGS. 2 and 3,the finger 80 has a plurality of spaced openings 82 and is mounted onthe end 78 by means such as a cotter pin 84 extending through one of theopenings 82. The cotter pin 84 also holds a spacer 86 which extendshorizontally away from the end 78. A trip reset mechanism 90 is providedand includes a lever arm 92 pivotally mounted on the support member 28between the ends 96 of the arm 92. A spring 94 is connected between theend 96 of arm 92 and the support member 28 and biases the arm 92downward toward engagement with spacer 86. The end 98 of the arm 92 isengaged by a spacer I held on link 46 by pin 50 when the contactoperating means 36 is in its closed position. As shown in FIG. 2, thearm 92 is pivoted to raise the end 96 of arm 92 above spacer 86 when thecontact operating means 36 is in its closed position. Raising the end 96of arm 92 also loads the spring 94. When the contact operating means 36is in its open position, as shown in FIG. 3, the end 96 of arm 92 isheld in a downward position by spring 94.

The operation of the trip mechanism 70 and reset mechanism 90 incombination with the contact operating means 36 is as follows. In FIG.2, the contact operating means 36 is shown in its closed position duringnormal load conditions in the section in which the sectionalizing switchis connected. During normal current conditions. the contacts 30 and 32will be closed, however, the current flowing through the solenoid coilwill not be sufficient to pull the plunger 52 downward. The plunger 52is thus in its upward position adjacent to the bottom of impulse valve64 during normal operating conditions of the sectionalizing switch.During normal closed conditions, the trip lever 74 is in its resetposition as shown in FIG. 2. Also, the trip reset mechanism 90 is heldin its loaded condition by the contact operating means 36.

When an overcurrent having a predetermined value occurs, the solenoidcoil 5] will pull the plunger 52 downward to cause oil 4 to be displacedto the top 53 of the plunger 52. Shortly after the overcurrent conditionoccurs, the aforementioned reclosing circuit breaker will interrupt thesystem so that the solenoid coil 5] is deenergized and the plunger 52 isbiased upward by the spring means 55 to force the oil 4 through theimpulse valve 64 and move the trip piston 72 upward a distancedetermined by the amount of oil forced through the valve 64. This is thefirst stepped movement of the trip piston 72 and does not affect thetrip lever 74 unless the finger 80 is set to a low position on the lever74. As shown in FIG. I, the finger 80 is secured to the lever 74 at amiddle one of the holes 82. In this position, the trip piston 72 doesnot engage the finger 80 to move the trip lever 74 to a trip position onthe first step of the trip piston 72. After a predetermined time period,the reclosing circuit breaker will close and again energize the system.If the overcurrent condition continues on the line in which thesectionalizing switch is connected. solenoid coil 51 will again pull theplunger 52 downward to displace oil 4 to the top 53 of plunger 52 andthe reclosing circuit breaker will open to deenergize the solenoid coil51. The spring means 55 then biases the plunger 52 upward to force oilthrough the valve 64 and step the trip piston 72 upward a second time.Depending on the position at which the finger is set, the trip piston 72may engage the finger 80 and move it upward to pivot the trip lever 74to a tripping position against the latch mechanism 40. It the finger 80is set at the middle one of the holes 82, the sectionalizing switch willbe tripped open upon movement of the trip piston 72 upward a secondtime. However, if the finger 80 is set at the highest one of the holes82, the trip lever 74 will not be moved far enough to trip the latchmechanism 40. In the latter case, upon the reclosing of the circuitbreaker, if an overcurrent condition continues on the line in which thesectionalizing switch is connected, the circuit breaker will open andthe trip piston 72 will be advanced another step upward. At this thirdstep of the trip piston '72, the trip mechanism 70 is moved to the tripposition in which the latch mechanism 40 is released. The toggle linkmechanism 38 is thereby collapsed to allow the opening spring means 42to move the contact operating means 36 to its open position as shown inFIG. 3. The reset mechanism is thereby released and the lever arm 92snaps downward to impact the spacer 86 under the force applied by thespring 94. This provides a quick reset action for the trip piston 72 andthe trip lever 74 so that the entire trip mechanism 70 is reset andthereby prepared to step through its switch opening operation incoordination with the reclosing circuit breaker.

A quick reset of the trip mechanism 70 is particularly important wherethe contact operating means 36 is manually moved to its closed positiona short time following an opening operation and the contacts 30 and 32are thereby closed. Under these conditions, the trip lever 74 will stillbe close to its trip position and, if a fault condition exists, thecontact operating means 36 will be immediately tripped to open thecontacts 30 and 32 before the reclosing circuit breaker has had anopportunity to deenergize the system. Since the contacts 30 and 32 ofthe sectionalizing switch are not rated for fault interrupting duty,interrupting of fault current will be damaging to them. Further, whenthe contact operating means 36 is moved towards its closed positionwhile the trip lever 74 is close to its trip position, the contactoperating means 36 will be tripped open before the opening spring means42 has been fully charged for an opening operation. This will result ina slower opening operation to the further damage of the switch contacts30 and 32. Another advantage of the quick reset means provided by theinvention is that a positive force is provided to overcome friction orforeign matter preventing reset movement of the trip piston 72.

Although a preferred embodiment of the invention has been illustratedand described, the disclosure is not to be limiting, for the inventionmay be variously embodied and is to be construed in accord with theclaims which follow.

lclaim:

1. In a circuit breaker including contact operating means having an openand a closed position, the combination comprising trip means having afirst and a second position and being movable from the first position tothe second position for releasing the contact operating means from itsclosed position and trip reset means responsive to the contact operatingmeans upon release from its closed position and spaced apart from thecontact operating means when the latter is in its open position formovably resetting the trip means from its second position to its firstposition, said contact operating means holding the trip reset means outof resetting movement when the contact operating means is in its closedposition.

2. The combination according to claim I wherein said trip reset means isengaged and disengaged with the contact operating means when the latteris respectively in its closed and open positions.

3. The combination according to claim 2 wherein said trip reset meansincludes resilient means and said contact operating means moves fromdisengagement to engagement with the trip reset means to load theresilient means when the contact operating means moves from its open toits closed positions.

4. The combination according to claim 1 wherein said trip reset meansmoves into impacting engagement with the trip means to move the latterfrom its second position to its first position when the contactoperating means is released from its closed position.

5. The combination according to claim 4 wherein said trip reset meanscomprises a pivotally mounted lever arm having an end connected to saidresilient means and an end engaged by the contact operating means whenthe latter is in its closed position, said arm pivoting into impactingengagement with the trip means when the contact operating means isreleased from its closed position.

6. In a circuit breaker including contact operating means having aclosed position. the combination comprising trip means having a trippiston having intermediate and trip positions and being movable from theintermediate to the trip position for releasing the contact operatingmeans from its closed position and trip reset means for resetting thetrip piston to its intermediate position from its trip position, saidcontact operating means holding the trip reset means out of resettingactuation when the contact operating means is in its closed position.

7. The combination according to claim 6 wherein said trip piston has anormal position and is free relative to said trip reset means to move tosaid normal position after being reset by said trip reset means.

8. The combination according to claim 6 wherein said trip means includesa trip lever engaging and releasing the contact operating means from itsclosed position when the trip piston is in its trip position, said triplever being moved into engagement with the contact operating means bythe trip piston.

9. The combination according to claim 6 wherein said trip means includesa cylinder, said trip piston being mounted within the cylinder, andmeans for pumping a fluid into said cylinder on one side of said pistonto move said piston from its normal to its trip position.

It). In a circuit interrupter connected to a line conducting current andincluding stationary contact means, movable contact means movable intoengagement with the stationary contact means and means for disengagingsaid movable and stationary contact means. the combination comprisingmoving means supporting said movable contact means for moving saidmovable and stationary contact means toward engagement with each otherand holding said contact means in said engagement. said moving meansengaging said disengaging means and including releasable means forpreventing operation of said disengaging means, tripping meansresponsive to current impulses in said line equal to or greater than apredetermined magnitude for counting said current impulses. saidtripping means having a first position and a second position and beingmovable from the first position to the second position for releasingsaid releasable means alter a predetermined number of current impulsesto allow operation of said disengaging means. and means responsive tosaid moving means for immediately resetting said tripping means to saidfirst position after releasing of said releasable means.

1]. The combination according to claim I0 wherein said resetting meansis responsive to said moving means only when the latter is moving themovable and stationary contact means toward engagement with each otherand holding said contact means in said engagement.

12. The combination according to claim ll wherein said moving means ismovable into and out of engagement with the resetting means.

IS. The combination according to claim l2 wherein said resetting meansand moving means are in engagement only when the latter is moving themovable and stationary contact means toward each other and holding saidcontact means in engagement.

I4. The combination according to claim 10 wherein said tripping meanshas a normal position and is movable between the normal position andsaid first position. said tripping means being free relative to saidreleasable means to return to said normal position after being reset tosaid first position.

1. In a circuit breaker including contact operating means having an openand a closed position, the combination comprising trip means having afirst and a second position and being movable from the first position tothe second position for releasing the contact operating means from itsclosed position and trip reset means responsive to the contact operatingmeans upon release from its closed position and spaced apart from thecontact operating means when the latter is in its open position formovably resetting the trip means from its second position to its firstposition, said contact operating means holding the trip reset means outof resetting movement when the contact operating means is in its closedposition.
 2. The combination according to claim 1 wherein said tripreset means is engaged and disengaged with the contact operating meanswhen the latter is respectively in its closed and open positions.
 3. Thecombination according to claim 2 wherein said trip reset means includesresilient means and said contact operating means moves fromdisengagement to engagement with the trip reset means to load theresilient means when the contact operating means moves from its open toits closed positions.
 4. The combination according to claim 1 whereinsaid trip reset means moves into impacting engagement with the tripmeans to move the latter from its second position to its first positionwhen the contact operating means is released from its closed position.5. The combination according to claim 4 wherein said trip reset meanscomprises a pivotally mounted lever arm having an end connected to saidresilient means and an end engaged by the contact operating means whenthe latter is in its closed position, said arm pivoting into impactingengagement with the trip means when the contact operating means isreleased from its closed position.
 6. In a circuit breaker includingcontact operating means having a closed position, the combinationcomprising trip means having a trip piston having intermediate and trippositions and being movable from the intermediate to the trip positionfor releasing the contact operating means from its closed position andtrip reset means for resetting the trip piston to its intermediateposition from its trip position, said contact operating means holdingthe trip reset means out of resetting actuation when the contactoperating means is in its closed position.
 7. The combination accordingto claim 6 wherein said trip piston has a normal position and is freerelative to said trip reset means to move to said normal position afterbeing reset by said trip reset means.
 8. The combination according toclaim 6 wherein said trip means includes a trip lever engaging andreleasing the contact operating means from its closed position when thetrip piston is in its trip position, said trip lever being moved intoengagement with the contact operating means by the trip piston.
 9. Thecombination according to claim 6 wherein said trip means includes acylinder, said trip piston being mounted within the cylinder, and meansfor pumping a fluid into said cylinder on one side of said piston tomove said piston from its normal tO its trip position.
 10. In a circuitinterrupter connected to a line conducting current and includingstationary contact means, movable contact means movable into engagementwith the stationary contact means and means for disengaging said movableand stationary contact means, the combination comprising moving meanssupporting said movable contact means for moving said movable andstationary contact means toward engagement with each other and holdingsaid contact means in said engagement, said moving means engaging saiddisengaging means and including releasable means for preventingoperation of said disengaging means, tripping means responsive tocurrent impulses in said line equal to or greater than a predeterminedmagnitude for counting said current impulses, said tripping means havinga first position and a second position and being movable from the firstposition to the second position for releasing said releasable meansafter a predetermined number of current impulses to allow operation ofsaid disengaging means, and means responsive to said moving means forimmediately resetting said tripping means to said first position afterreleasing of said releasable means.
 11. The combination according toclaim 10 wherein said resetting means is responsive to said moving meansonly when the latter is moving the movable and stationary contact meanstoward engagement with each other and holding said contact means in saidengagement.
 12. The combination according to claim 11 wherein saidmoving means is movable into and out of engagement with the resettingmeans.
 13. The combination according to claim 12 wherein said resettingmeans and moving means are in engagement only when the latter is movingthe movable and stationary contact means toward each other and holdingsaid contact means in engagement.
 14. The combination according to claim10 wherein said tripping means has a normal position and is movablebetween the normal position and said first position, said tripping meansbeing free relative to said releasable means to return to said normalposition after being reset to said first position.